近日，南京大学周豪慎团队研究了用于阻燃高性能钠金属电池的定制溶剂-溶剂相互作用的电解质。该研究于2025年6月18日发表在《德国应用化学》杂志上。

钠金属电池（SMB）因其丰富的钠资源和高能量密度而受到广泛关注。然而，电解质和钠金属阳极之间的连续反应，以及不稳定固体电解质界面（SEI）的形成，会导致容量快速衰减和潜在着火的安全隐患。在这项工作中，研究组通过将NaDFOB作为单一盐引入基于磷酸三甲酯的酯基电解质中，实现了设计一种具有溶剂-溶剂相互作用的低成本阻燃电解质。 

理论研究与实验研究相结合揭示，通过溶剂-溶剂相互作用，在低浓度下形成富含离子聚集体的溶剂化结构，导致在阳极上形成富含B和F等无机化合物的梯度SEI。这有效地抑制了界面反应和钠枝晶生长，显著提高了循环稳定性，同时优化了SMB的安全性。使用这种电解质的Na₃V₂（PO₄）₃电池在1C下5000次循环（320天）后保持93%的高容量保持率。这种方法为中小型企业应用阻燃电解质提供了一种可靠的解决方案，也阐明了先进电池系统的设计原理。

附：英文原文

Title: Electrolytes with Tailored Solvent-Solvent Interactions for Flame-Retardant High-Performance Sodium-Metal Batteries

Author: Zhangbin Cheng, Zehui Zhang, Mingtian Wu, Min Jia, Xinyi Du, Zheng Gao, Shuai Tong, Tao Wang, Xiaohong Yan, Xiaoyu Zhang, Haoshen Zhou

Issue&Volume: 2025-06-18

Abstract: Sodium metal batteries (SMBs), which possess abundant sodium resources and high energy density, have attracted widespread attention. However, the continuous reaction between the electrolyte and the sodium metal anode, along with the formation of an unstable solid electrolyte interphase (SEI), leads to rapid capacity decay and the safety hazard of potential ignition. In this work, designing a low-cost and flame-retardant electrolyte with solvent-solvent interactions is achieved by introducing NaDFOB as a single salt into the ester-based electrolyte on the basis of trimethyl  phosphate. Theoretical research combined with experimental study disclose through the solvent-solvent interactions, an ion-aggregate-rich solvation structure is formed at low concentrations, leading to the formation of a gradient SEI enriched with inorganic compounds such as B and F on the anode. This effectively suppresses interfacial reactions and sodium dendrite growth, significantly improving the cycling stability along with the optimizing the safety of SMBs. The Na||Na3V2(PO4)3 battery using this electrolyte maintains a high-capacity retention of 93% after 5000 cycles (320 days) at 1C. This approach provides a reliable solution for the application of flame-retardant electrolytes in SMBs which also sheds light on the designing principle of advanced battery systems.

DOI: 10.1002/anie.202503864

Source: https://onlinelibrary.wiley.com/doi/10.1002/anie.202503864